1. Field of the Invention
The present invention generally relates to vehicular control pedals, such as brake, clutch, and accelerator pedals. More specifically, this invention relates to an adjustable vehicle control pedal system having a compact arrangement where the pedals can be selectively adjusted to allow optimum positioning of the pedals relative to an operator of a vehicle.
2. Description of Related Art
Vehicles are conventionally provided with foot-operated control pedals, such as accelerator, brake, and clutch pedals that are used to control the speed of the vehicle. Typically, these control pedals are rigidly fixed to the vehicle body and rotate or pivot away from the driver when foot pressure is applied, and are not adjustable relative to the driver or their respective attachment points. Consequently, the control pedals must generally be attached and positioned relative to the driver of the vehicle to enable operation that is adequately safe and comfortable for the xe2x80x9caveragexe2x80x9d driver. However, some adjustment of the driver""s position relative to the control pedals is clearly desirable since the vehicle and its controls must accommodate drivers of various physical attributes. Until recently, this adjustment was accomplished only by adjusting a driver""s seat.
Though the driver""s seat is usually mounted so as to be slidable in a fore and aft and up and down direction to accommodate drivers of different physiques, such an arrangement is only partially effective in positioning the driver relative to the control pedals. Seat adjustment allows the driver to position himself or herself relative to the vehicle""s steering wheel and the control pedals, to some degree improving the driver""s comfort and facilitating the driver""s ability to operate the vehicle""s primary controls. It is, however, nearly impossible for such a solution to accommodate all possible variations in the human frame. In particular, proportional differences between the lengths of a driver""s arms, legs and feet in relation to the driver""s overall physique cannot be readily accommodated by merely adjusting the seat fore and aft or up and down with respect to the control pedals. Accordingly, it has been recognized that some form of control pedal adjustment is desirable to provide optimal comfort and safety to the driver while also ensuring that the driver can fully operate the control pedals at all times.
Generally, many approaches to providing adjustable control pedals have resulted in pedal systems having an abundance of expensive parts in complex arrangements that occupy a substantial amount of space within a vehicle. Specifically, lever mechanisms are known in the prior art, and the adjustment of one lever with respect to another concentrically mounted lever can also be found in wear or slack adjuster mechanisms. For example, Tack, U.S. Pat. No. 2,550,731, and Tack et al., U.S. Pat. No. 2,550,732, teach a manually operated screw mechanism that is threaded into one lever and operatively connected to associated hangers for adjusting the slack conditions in the brake rigging. Adjusting of the lever with respect to the hangers and simultaneously modifying the position of the lever where it is connected to the associated brake rigging allows for wear adjustment.
Many other approaches to providing adjustable control pedals have also been suggested in the prior art. One approach is to provide some form of ratchet device that allows the entire control pedal assembly to rotate about a primary pivot point. This approach rotates a housing to which the control pedals are each rotatably attached, thus providing rotation of the control pedals in unison relative to the driver. Examples of this are illustrated in U.S. Pat. Nos. 3,282,125 to Dully; 3,400,607 to Smith; and 3,563,111 to Zeigler. A similar approach is to mount one or more control pedals to a housing, attached to the body of the vehicle, that is slidable fore and aft as a unit relative to the driver, as illustrated in U.S. Pat. Nos. 2,860,720 to Huff et al.; 4,683,977 to Salmon; 5,010,782 to Asano et al.; and British Patent No. 952,831 to Mussell. As taught by Asano et al., the entire housing and pedal assembly rotates about a single pivot point during actuation of the pedals. A disadvantage with pedal systems such as that of Asano et al. is that a spring is required to return the pedal and housing assembly to its initial position, necessitating that the driver also overcome the force generated by the spring in order to actuate the pedal, resulting in an increase of brake pedal effort.
Another suggested approach is a variation on those previously mentioned, employing a screw-actuated device to displace a housing to which one or more control pedals are rotatably mounted. The screw-actuated device can be used to either rotate the entire housing about a pivot point, as shown in U.S. Pat. No. 3,151,499 to Roe, or the screw-actuated device can displace the housing fore and aft, as illustrated by U.S. Pat. Nos. 3,301,088 to White; 3,643,525 to Gibas; 3,765,264 to Bruhn, Jr.; 4,870,871 to Ivan; 4,875,385 to Sitrin; 4,989,474 and 5,078,024 to Cicotte et al.; and 5,460,061 to Redding, et al. Typically, the screw-actuated device is disclosed to be driven by an electric motor that allows the control pedals to be selectively adjusted by the driver from an appropriate actuator switch mounted on the dashboard of the vehicle within the driver""s reach.
A further attempt to provide a solution for this problem is disclosed by Rixon et al. in U.S. Pat. No. 5,632,183, wherein a pedal assembly is mounted on a single hollow guide rod extending forwardly from a transmission housing that is pivotably mounted to a bracket secured to a body portion of the vehicle. A helical ball and nut assembly is positioned within the single hollow guide and extends from the transmission housing. A key extends from the nut to the pedal assembly that is mounted to the outside diameter of the single hollow guide so that linear movement of the nut along the helical thread within the hollow guide generates linear movement of the pedal assembly along the hollow guide rod, in forward or rearward directions.
As can be readily appreciated by those skilled in the art, the above examples all require substantial amounts of hardware and space beneath the vehicle""s instrument panel to accommodate the device and its associated structure providing the adjustment features. Much of the necessary additional hardware can be attributed to the need to avoid affecting the operation of the brake and/or clutch pedals, during adjustment, with their respective power sources.
From the above discussion, with the exception of the recent Cicotte patents, it can be readily appreciated that the prior art does not disclose a vehicle control pedal arrangement that entails minimal additional hardware to achieve suitable adjustment of one or more control pedals that can be used with a conventional control pedal packaging arrangement without significant structural changes.
An additional problem in adapting adjustable pedal systems to an existing vehicle is that of interference of the pedal hardware with pre-existing structural members such as a steering column. The additional hardware and increased operating envelope of the adjustable pedal system make interference with a steering column more likely. Therefore, it is necessary to design the adjustable pedal system around such structural members, rather than relocating the structural members, so that the adjustable pedal system can be xe2x80x9cdropped in placexe2x80x9d under the dash of an existing vehicle design.
One related approach was discussed in U.S. Pat. No. 4,022,081 to Dodd et al., that teaches use of a brake pedal having a pedal adapter that allows use of a bent lever arm to avoid obstruction with a stationary member. Dodd et al. disclose a pedal adapter intermediate a push rod and brake lever, where the pedal adapter is offset at a predetermined angle to permit the brake lever to be bent around the steering column to avoid interference therewith. While this solution may suffice for traditional pedal designs, it does not solve the packaging problems of modem adjustable pedal systems. The additional hardware and increased operating envelope of modern adjustable pedal systems demand a more forgiving arrangement. Additionally, it is undesirable to incorporate a bend in the pedal arm. Such a bend may be apposite only in certain vehicle models and not in others. Accordingly, it would be necessary to manufacture multiple versions of the pedal arm to accommodate the different vehicle models. This increases pedal assembly model mix and complexity of vehicle assembly.
Accordingly, what is needed is a cost-efficient adjustment device for adjusting one or more vehicle control pedals, as well as foot rests. The adjustment device is capable of spatially adjusting the control pedals without repositioning the pivot attachment of the conventional control pedal arrangement to adapt to the physical and physiological demands of a driver, and is simultaneously cost effective by requiring minimal structural components and modifications to achieve the desired functional and safety results. Additionally, the adjustment device must also have a connection configuration between a pedal lever and a reaction member that avoids interference with pre-existing structural members.
A compact adjustable pedal system is provided that meets the above-mentioned needs of the prior art. The adjustable pedal system is provided for adjusting a pedal with respect to a datum on a reaction member of a vehicle, such as a brake booster pushrod eyelet, or the head of an accelerator cable. A bracket or support is mounted within the vehicle and establishes at least one axis of actuation for the adjustable pedal system. A pedal arm includes a pivot end that is pivotally mounted about the axis of actuation. The pedal arm extends from the pivot end and terminates in a pedal end having the pedal attached thereto. A slave arm is also mounted to and pivotable about an axis of actuation. The slave arm includes an adjustment end opposite the pivot end. A powered screw adjustment device connects the pedal arm to the slave arm and is positioned for pivoting the pedal arm with respect to the slave arm.
In one embodiment, the adjustment device pivots the pedal arm about the axis of actuation. In another embodiment, the adjustment device pivots the pedal arm about an axis of adjustment at an offset end of the pedal arm.
Accordingly, it is an object of the present invention to provide a vehicle pedal system that is capable of adjusting the positions of control pedals relative to a predetermined datum, such as the pushrod eyelet of a brake booster, or the end of an accelerator or clutch cable, etc.
It is another object of the present invention to provide an adjustable pedal system that is capable of adjusting the positions of one or more vehicle control pedals and that is more compact relative to the prior art.
It is yet another object of the present invention that the adjustment device requires minimal additional hardware so as to minimize the structural modifications required to adapt the adjustment device to a pre-existing vehicle compartment.
It is still another object of the present invention to provide an adjustment device for a vehicle control pedal that reduces the cost of assembly and may drop in place on a current production vehicle.
It is a further object of the present invention to use a lead screw that may be rotated by a manually or electrically driven adjuster mechanism in order to displace the control pedal arm with respect to a datum without any movement of the datum.
It is still a further object of the present invention to provide an adjustable control pedal that uses a compact electric motor with limited movement during operation thereof and is economical and easy to manufacture.
It is yet a farther object to provide an adjustable pedal system that reduces the number of components, reduces the cost of assembly, and requires a single pedal pivot axis such that the system is easily adaptable to an existing pedal mount of a production vehicle.
It is an additional object of the present invention to provide an adjustment device for vehicle control pedals that avoids interference with structural members.
It is yet an additional object of the present invention to provide an adjustment device for vehicle control pedals that can be readily adapted to a pre-existing vehicle compartment without having to relocate any structural members, such as a pre-existing steering column, from its current position.
These objects and other features, aspects, and advantages of this invention will be more apparent after a reading of the following detailed description, appended claims, and accompanying drawings.